Tooth-crown.



. No. 636,568. Patented Nov. 7, I899.

L. S. SEELEY. TOOTH CROWN.

(Application filed Dec. 2, 1898.)

WITNESSES afim w A TTORNE UNITED ST TES PATENT OFFICE.

LEWIS S. SEELEY, OF NEW YORK, N. Y.

TOOTH-CROWN.-

SPECIFICATION forming part of Letters Patent No. 636,568, dated November 7, 1899.

Application filed December 2, 1898.

To all whom it may concern:

Be it known that I, LEWIS S. SEELEY, a citizen of the United States, and a resident of the city of New York, in the county and State of New York,have invented certain new and useful Improvements in Artificial Tooth-Crowns, of which the following is a specification.

The invention relates more especially, to that class of crowns which are fitted and attached to a natural root. i

The objects are to so construct the shank or pin with which the crown is provided as to afford a better meansthan heretofore for securing the crown to the root, the shank also being adaptable to a double as well as a tooth having only one root.

To these endsthe invention consists in the construction, as hereinafter more fully described, and pointed out or indicated in and by the claim.

In the drawings, Figure 1 is an enlarged sectional View of a tooth-crown, the shank, and a root, to which it is secured by cement or filling. Fig. 2 is an enlarged section of a crown and of the shank, with separated ends of the wire or strip of metal bent at an angle to the shank. Fig. 3 is an enlarged sectional View of a crown and the shank, which is here baked therein in the usual manner.

shown as being spread or shaped to extend across the cavity in the root and brace the shank against the sides thereof when attaching the crown. In these several figures the end of the shank is shown as being tapered, while in Fig. 4, which is an enlarged view of the shank alone, no point or tapering is shown at the return-bend or end of the shank.

In the drawings, A represents the crown, which may bemade of porcelain or plastic material. The upper end a of the shank B is inserted in the material while plastic and The shank is made of a strip of metal or wire, which is doubled so that the return-bend 1) forms the end. The metal strips or wire may be round, fiat, or angular, but I prefer the latter, and they are usually of platinum or platino-iridium, though any 'othersuitable metal may be used. The two parts are brought close to each other at or near the return-bend or end I) of the shank, thus allowing a taper and even a point to be made at the extremity which extends deepest into the canal of the root 0 of the natural tooth. This taper or point may be made either at the time of manufacture or when the crown is being fitted to Serial No. 698,118. (No model.)

the root on which it is to be secured.- If the tooth has a double root, the return-bend may be cut or filed so as to allow of a separation of the parts of the shank, which, being spread,

will form two shanks one for each root. A space a is left between the two parts after leaving the return-bend, so as to admit the cement or filling, which will form, as it were, a bridge or solid mass across the canal of the root. This, together with the hold which the cement takes on the walls of the root, will se cure the crown more firmly than where dependence is placed entirely upon screwthreads, flanges, or other conformations on the exterior of the shank.

The doubled metal strip or wire of which the shank is formed is capable of being spread to extend across the cavity in the root, bracing the shank against the sides thereof and leaving an enlarged opening (1 between the strips, which will be filled with the cement. Such adjustment and bracing of the shank holds the crown steady while thevcement is hardening or until it is set, and also makes the crown much more firm, so that mastication of food is less liable to jar or loosen the shank by a continued use of the tooth thus repaired. Moreover, a crown provided with a shank formed of a doubled strip or wire such as I have shown and described is simple in construction and cheap to manufacture, in which pered shank formed of a single wire, the two lengths of which are spaced apart and converged at their outer connected ends and baked with the crown at their inner ends; whereby the shank will conform to an ordinary tapered tooth-cavity, or may be bulged outwardly to conform to the cavity of differ- IOO ent shape or may be divided at its outer extremity or point to form two prongs for a dou ble cavity, substantially as set forth.

. LEWIS S. SEELEY. Witnesses:

HENRY T. BRENNAN, M. H. SMALL. 

